package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.BeanUtils;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;


@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;
    //关注用户修改数据库被关注用户的id
    @Override
    public Result follow(Long followUserId, boolean isFollow) {
        //获取当前用户的id
        Long userId = UserHolder.getUser().getId();
        String key = "follows:" + userId;
        //判断当前是否关注
        if (isFollow) {
            Follow follow = new Follow();
            follow.setFollowUserId(followUserId);
            follow.setUserId(userId);
            boolean isSuccess = save(follow);
            if(isSuccess){
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        }else {
            boolean isSuccess = remove(new QueryWrapper<Follow>().eq("user_id", userId)
                    .eq("follow_user_id", followUserId));
            if(isSuccess){
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }
        return Result.ok();
    }

    //前端查询是否关注
    @Override
    public Result followed(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        //查询是否存在关注关系
        Integer count = query().eq("user_id", userId)
                .eq("follow_user_id", followUserId).count();
        return Result.ok(count > 0);
    }

    //查询其他用户的共同关注
    @Override
    public Result followCommons(Long id) {
        //当前用户id
        Long userId = UserHolder.getUser().getId();
        String key = "follows:" + userId;
        String key2 = "follows:" + id;

        //使用命令查询set集合交集
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if(intersect == null || intersect.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //查询具体用户返回
        List<UserDTO> userDTOS = userService.listByIds(ids).stream().
                map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
